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What is the lift force per unit span?
I got Aircraft Design: A conceptual approach for Christmas, and I'm having a hard time with lift coefficients because I honestly have no idea what "lift force per unit span" means, so can someone please explain this to me?

If the total lift of a wing is L, and the span of the wing is X, then isn't the lift per unit span just L/X?

It's not a rectangular wing, and it also has an uneven taper.

So the question now becomes, how to find the mean aerodynamic chord of a wing that does not have a straight leading and/or trailing edge.

Maybe the book is just talking about a thin slice of the wing then.  Lift per span might mean (delta L)/(delta X).  In answer to your latest comment: No, chord and span are different measurements.

Yes, yes they are. I get things mixed up sometimes. Thanks.

Taking a guess here because I can't see the book...  I have a feeling that the point is that lift is proportional to wing area which is roughly chord times span.  If you just want to focus on the effect of wing shape in the chord direction, then it makes sense to divide out the span.

Let us continue this discussion in chat.

@ptgflyer Can you tell where exactly this phrase comes? That would be better.

Mind if I ask how readable you find that book and what engineering background you have? I'm looking for a good book on the basics of aircraft design that doesn't require a degree to read.

Have you already wrote down the design on a sheet of paper. I kind of want to see a picture of it. Very curious to see new concepts.

@TomMcW: I'm a freshman in high school, no engineering background. I find most of it readable and the few things I've been confused about have been easy to find (except for this)

@Ethan: It's not my design, I'm doing an analysis of a design in the book. It's a canard ASW design.

The concept of lift force per unit span comes from potential flow theory. It will need some background information to explain what it means, so bear with me.
In the early years of flight, electricity was new and exciting, and it just happened that the equations which could calculate the strength of an electromagnetic field worked equally well when calculating the local flow change effected by a wing. What is the electrical current in a wire became the vorticity in a vortex, and the strength and orientation of the induced magnetic field were equivalent to the induced flow changes. So the vocabulary of electricity was copied over to aerodynamics, just like brain research used vocabulary from computer science when that was a hot topic.
Now we are left with abstract concepts like induced drag or lift per unit span. It would be so much more descriptive to use proper names, but the authors of technical books learned it that way and are much too lazy to explain aerodynamics any better.
In potential flow theory, you have sources, sinks and vortices. Sources and sinks are used to generate the displacement effect of a physical body moving through air, and vortices are used to explain why wings bend the flow and create lift. In order to calculate the lift force $L$ of a single vortex in two-dimensional flow, the circulation strength $\Gamma$ of the vortex is multiplied by the airspeed $u_{\infty}$ and air density $\rho$. You will find an equation like $L = -\Gamma\cdot u_{\infty}\cdot\rho$ in many treatises about numerical aerodynamics.
To expand that into the third dimension (and, consequently, into reality), you need to add something measured in spanwise direction - but you have already lift, and adding the third dimension would give a moment (lift times distance) where only lift would make sense. Therefore, this two-dimensional lift is now called "lift per unit of span" so there is still space for a third dimension where two-dimensional flow did already produce lift (counter to any sound intuition).
And no, this is never constant over span. In all cases the vorticity is gradually reduced towards the tips, or explained in a better way, the suction force acting on the wing is gradually reduced when you approach the tips because when the wing ends, nothing can prevent the air from flowing from the high-pressure region below to the low-pressure region on the upper surface of the wing.
While the potential flow mentioned above is the mathematical way of looking at aircraft, lift coefficients are the engineer's way of expressing things. From tests it was soon clear that the lift force of a wing scales with the dynamic pressure $q$ of the flow, that is the product of air density and the square of airspeed: $q = \frac{\rho}{2}\cdot v^2$.
The next observation of engineers was that lift also scales with wing area $S$. To make the lifting force independent of wing size and dynamic pressure, they stripped both from the lift (physical unit of Kilopond, Newton or pound-force) so they arrived at a dimensionless figure which they called lift coefficient $c_L$. Doing so made it much easier to compare measurements or scale up known designs for the next, better design. The lift equation now becomes $L = c_L\cdot S\cdot\frac{\rho}{2}\cdot v^2$

Another excellent answer, helpful even for us knuckle-dragging operators who never got too far past the "houses bigger/houses smaller" explanation of flight controls!  In your 4th paragraph, you talk about the "strength of the vortex" -- which I visualize as the swirl coming off the wingtips -- a 3D phenomena. In the 2D context, what does "vortex" refer to here? Thanks!

@RalphJ: In the 2D context this is just something which swirls the air, like the drain of a bathtub viewed from above (if you allow for the column of water to have zero height, ideally). Also, this swirl is not coming off the wingtip, but in a sheet of infinite swirls along the whole span. Another detail the lazy authors mostly get wrong.

Imagine that the wing is a carrot, and chop it up as you would chop a carrot into discs. The lift (force) produced by a slice of thickness 1 is the lift (force) per unit span of that slice. ("Thickness 1" could be in whatever units you choose, so another way to look at that is to divide the lift by the thickness of the slice.)
For a uniform (straight, not tapered, swept, or twisted) wing, every slice produces the same amount of lift, so as Riccati points out, the lift per unit span is just the total lift divided by the wing span. However, on a wing whose shape varies from the fuselage to the tip, each slice is slightly different. A tapered wing might look a bit like a very conical carrot, and the lift per unit span decreases smoothly from the root to the tip, just like the diameter of each disc decreases as you get towards the tip of the carrot. (I'm not saying the shape of the carrot is related at all: it's just a way of thinking about considering each slice separately.)
While you can use total lift to compare different wings, you can use lift per unit span to compare wings in a way that's independent of their span. A wing twice as long will produce twice the lift (ignoring real-world effects like flex and prop wash), but it will have the same lift per unit span, because it has the same thickness and shape as the shorter wing. More usefully, you can use it to look at different parts of the same wing: to compare the root and the tip. Later in your book, you'll see charts showing how the lift per unit span varies along the length for different shapes/designs of wing.

Consider a finite (three dimensional) wing producing lift. It would be difficult for us to calculate the total lift and exact lift distribution of the wing unless it is quite simple.
One way to deal with it is to 'slice' the wing into a number of segments for which the lift force can be found and the take into account the effects of variation of various wing parameters like:

Chord
Geometric twist
Aerodynamic twist (airfoil shape).

The lift per unit span of the wing can be found from the lift coefficient of the airfoil- basically, we are assuming that the flow over a finite wing can be treated as locally two-dimensional and finding the forces on the wing using this.
As an example, take a three dimensional wing and then slice it into small pieces so that the lift is essentially constant within each (i.e. the airfoil section and angle of attack is constant). For each of the slices, it is possible to find the lift (from airfoil and flow characteristics). This gives the lift per unit span (unit span here means the size satisfying above conditions).
Now, the total lift can be found by simply adding the lifts from various sections. Another thing is that the spanwise variation of the lift per unit span gives the lift distribution of the wing- helping us to compare various wing planforms- like elliptical vs rectangular etc.

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What causes a run-away propeller?
I've never understood this, why can't you just idle the engine and let it slow down?

In the case of the one propeller overspeed I experienced, idling the engine reduced the overspeed, but it was still well above red line. The only way I knew that closing the throttle reduced the overspeed was that the noise, which was considerable, lessened somewhat. The cause of the overspeed was found to be congealed oil in the propeller hub. The airplane had set outside for three nights in sub-zero temperatures. The aircraft was a Cessna 310. The overspeed occurred right after raising the gear. I was alone in the airplane.

Often the overspeed is caused by the airflow forcing the propeller to move faster. It's like braking on the engine while going down a steep hill, even without touching the gas pedal you may speed up and redline the engine. Very problematic if you already overheated your brakes in a 18 wheeler.
If you have a variable pitch prop you can feather it to reduce the effect of the airflow. Or just follow the procedures in the overspeed checklist for the aircraft.

Of course usually the reason for the overspeed is that the pitch control failed, so you may not be able to feather it. Otherwise variable pitch propellers are generally constant speed, so they automatically adjust pitch to avoid overspeeding when the pitch control works.

But wouldn't you be able to pull up and slow the airflow?

@ptgflyer slowing down could cause the plane to stall and would not necessarily be enough to slow down the prop.

That's a good point.

According to this FAA document, reducing power and airspeed is recommended - https://www.faasafety.gov/files/gslac/library/documents/2010/Jun/43935/FLYING%20LESSONS%20100603.pdf. Basic airmanship should be employed to avoid stalling the airplane.

Overspeed propeller is caused by a governor malfunction: instead of aligning itself so that it experiences a decent amount of torque to overcome, the blade pitch springs back to minimum pitch. A good pitch for take-off, but not at speed since there is no resistance anymore, in fact the prop can be back driven by the airflow in this scenario.

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What is Jet-A made of?
I know that it is kerosene based, but what exactly goes into it? Proportions of the various components would be helpful.

Its made with pure kerosene and anti freeze. (https://en.wikipedia.org/wiki/Aviation_fuel) This is where I got the information.

@fooot -- I'm not thinking of this as a dupe b/c it focuses in specifically on jet fuel, vs the "what fuels are out there?" of the linked Q -- they're certainly related, though.

@UnrecognizedFallingObject but answers to the linked question still explain what the components are, as well as other fuels.

Its a base of unicorn juice. Thats the only way to make a machine fly.

Sadly, that information's pretty much impossible to give a general answer for, as it changes from batch to batch:

Refineries blend crude "to taste" as well as pricetag, so to speak, and the crude blend used as the refinery feedstock may change from batch to batch.
Process conditions in catalytic crackers and reformers can change depending on the point in the batch you're at, the incoming feedstock, and even the history of prior batches (say the last thing that ran through the cat cracker degraded the catalyst slightly...)
Jet fuels as-delivered may be a blend of multiple refinery batches and even the output of multiple refiners
Pipeline batching can also lead to subtle changes in fuel composition as it is transported -- pipeline operators try to "cut off" as much of the transmix as they can, but 100% isn't easy without wasting tons of fuel as transmix.  (Some pipeline operators will stick a "dumb pig" between high spec products, such as jet fuel, and their neighbors in the pipeline, but this is by no means universal.)

That said, you can make some determinations based off of a representative SDS for Jet-A, courtesy of ConocoPhillips:

The fuel consists of medium-weight hydrocarbons, from C9 to C16
The only specified aromatic component is napthalene, with a maximum concentration of 3%
No additives (anti-static, FSII, anti-oxidation, biocidal) are specified -- these are generally variable from batch-to-batch, depending on the specific purchaser (a large airport might get to spec these directly with the refiner, while the small GA 'dromes are at the mercy of whoever pulls up in the fuel truck)

I'd always been told that all aviation fuel was strictly controlled, to be essentially the same no matter where it's bought. These differences in batches & blends must have practically zero effect on engine performance, right?

@Xen2050 -- Yes -- the ASTM/... specs for Jet-A control all the important properties well enough that jet fuel is a commodity product -- any batch of Jet-A that meets spec will function "as advertised" in anything type certificated to run on Jet-A.  (If you really wanted to know the exact makeup of a batch of jet fuel, you'd probably need to ask a friendly chemist to assay the batch, but that's expensive, tedious, and generally unnecessary as the Jet-A spec is largely performance based anyhow.)

@Xen2050, the differences do have practically zero effect on engine performance, but not because they are small. It's because the engines will run on about anything as long as it has sufficient specific heating value, ignition temperature in the right range and is slippery enough to keep the fuel pumps happy.


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What does the condition lever in turboprops control?
Turbojet and turbofan engines have just one control lever that controls the thrust by setting the amount of fuel injected.
But most turboprop aircraft have three levers. One adjusts the fuel flow, one adjusts the propeller speed, but what does the third one do? Does it only act as an on-off switch as simulators tend to present it?

Shamelessly quoting from Skybrary: (emphasys mine)

A Condition Lever is a pilot actuated control which is located within
  the throttle quadrant of a turboprop engine equipped aircraft. It is
  utilised to control some functions of both the propeller and the
  engine. These functions vary from installation to installation.
Functions of the condition lever can include any of the following:

Fuel cut-off.
Propeller feathering.
Propeller un-feathering.
Low idle/high idle selection.
Propeller speed control.

More details from Avcanada.


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Is a pilot who steals an airplane considered PIC?
Bob is a certificated ASEL private pilot. He steals Jane's Cessna 172 and flies it. He buys the fuel for the flight at his own expense, and after the flight, he pays Jane a reasonable rental rate. (In other words, he is not getting flight hours for any less money than he could by legal means, so there's no possible compensation issue.) The flight would have been completely legal if he had had Jane's permission. Is he considered the pilot in command while flying the stolen plane for the purpose of logging flight time?

He certainly is the pirate in command! (scnr)

If you steal a car are you the driver of that car?

@MichaelHall yes, and the plane thief is definitely the "pilot flying," but since "pilot in command" is a title given by law, it wouldn't be surprising if someone flying illegally is not considered PIC.

@MichaelHall yes, for logging time.

Are you asking for the purposes of logging that time? Who would responsible in the event of an airspace violation or mishap, or what? There needs to be a reason for the distinction to be meaningful, otherwise PIC is just a “title” without real significance.

Local prosecutor: "Yes, please do fully log that time. Also, I'll be taking that logbook when you're finished..."

@reirab, would logging time be protected against self incrimination?!  ;)  (felons are specifically exempted from being required to register firearms...)

@MichaelHall In the sense that you would not be required to log the hours, I suppose so. If you do log them, though, then you're probably out of luck unless your log is a purely digital one stored on an encrypted device. :) (And, even then, as I recall, there's currently still a circuit split on whether you can be compelled to provide the password, so that may depend on which part of the country you're in.)

I would think a real version of this scenario would be a pilot is flying an airliner quite normally, but there's a dispute between the airline and the lessor, where the finance company is trying to get the leased plane back because, e.g. they haven't been paid.

The FAA doesn't have the authority to decide if you had stolen the aircraft you've been flying. Only a criminal court can determine that. The FAA may then act on the court's decision.
The FAA may issue licenses to convicted felons, unless the conviction was for addiction-related offenses. However, the FAA does require that ATP applicants be of good moral character. There's been a relevant question - What does the FAA consider to be "good moral character"? - and felonies trigger an inquiry.
There is no separate FAA-imposed penalty such as not logging the time spent committing a crime - the regulations do not address that. Generally FAA rules suggest logging the time, even if some regulations were violated. The one requirement that matters is that the pilot is in control, including having the required skills.
Realistically, since pilots fill their logbooks themselves, it would be up to the pilot's conscience to log or not log the time. It would usually not be obvious to anyone reading the logbook whether the aircraft was operated with the owner's permission. For FAA purposes, that is not important per se.

14 CFR §61.51(e) covers logging PIC time.
It does not include legal ownership of the aircraft or a valid rental contract as one of the prerequisite conditions, therefore a thief may log PIC time provided they meet all other provisions of this section.

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Can you try for a second class medical, then get a third class if you fail, for the cost of one exam?
I'm virtually certain that I qualify for a third class medical, and likely for a second class. (I know I could qualify for second, but I'm not sure I have 20/20 vision with my current glasses.) Can I go to an AME for a second class medical, then get a third class if I don't qualify, without paying for two exams?

The answer will likely vary by AME.

Not only should you get a separate eye exam first, if you have the doctor fill out FAA Form 8500-7 (Report of Eye Evaluation) while you're there, you don't even need to do the vision test when you're with with the AME.

Michael Hall's comment is, I believe, correct.
The circumstances of my last exam were what happened to me, and my AME just gave me the third class.
Interestingly, I had filled out the online form requesting a second class. I clearly saw the AME change that to a third class, but when the medical came, it was a second class.
I didn't complain.
My AME charges the same for second and third class medicals, so there was no adjustment of the charge.

For a failed eye exam specifically, probably. AME pricing is almost completely up to the AME, though. So you would need to ask them to be sure.
Keep in mind that if you are over 35, a 2nd class exam will also involve an electrocardiogram. If you fail that, it will also probably disqualify you from a 3rd class. Just because a 3rd class doesn't require an electrocardiogram doesn't mean you can ignore whatever medical problem the electrocardiogram found.
But never go into a medical knowing you might fail it! If you want a 2nd class medical, just go get an eye exam (and new glasses, if necessary). Even if you go in for a 3rd class, an eye exam would be wise to be sure you'll make 20/40. It's simply not worth the hassle of having to deal with the AMCD.
As an aside, my vision is about 20/40 uncorrected. And I can tell you that there is no way I would ever want to fly without my glasses on. Finding traffic can be hard enough even with perfect vision- you're doing yourself a big favor by getting a glasses prescription that's actually correct.

Thank you! I'm under 35, so the ECG isn't an issue. My corrected vision is definitely a lot better than 20/40; I'm just not sure it's quite 20/20.

@Someone I would strongly encourage you to just get an eye exam. If you're planning to get into aviation, the price of an eye exam and a cheap new pair of glasses is a rounding error in the cost of your PPL training. ;) And really perfect glasses make a big difference over almost perfect glasses over the distances involved in aviation.


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What would happen if you tried to take off in a vacuum?
What would happen if the pilot of a pressurized rocket-powered airplane-shaped vehicle attempted to take off in a vacuum? I would expect the plane to just taxi no matter what the pilot did; is this correct?

It would depend if there was gravity.  Small asteroid, no problem.

@RobertDiGiovanni in that case it can only fly forward unless the rockets can be gimballed, right?

You could get very different results depending on the runway.  https://aviation.stackexchange.com/questions/8805/is-it-possible-to-go-around-at-lukla-airport https://aviation.stackexchange.com/questions/32694/what-are-the-difficulties-of-landing-on-an-upslope-runway

It would depend on how high the pilot could raise the nose. The wings aren't doing anything and you might as well remove them. If a rocket were just rolling along the ground with no atmosphere, well it's a rocket car and you might as well take it to Bonneville Salt Flats and try to set a record with it. Without an atmosphere, the speed of the car would only be limited by rolling friction.
To get it to lift off the surface, you would have to tilt the thrust line enough that the vertical component of thrust created was enough overcome gravity.  You could do this, say with the thing tilted at 45 degrees, with another lateral rocket under the nose to lift it. At 45 degrees your 100,000 lb rocket engine would be making just under 71000 lbs in the vertical plane, and same on the horizontal plane. If the machine weighs, say, 50000 lbs, it'll take off.
Of course, you can stand it straight up and get ALL of the thrust working to oppose gravity, and do away with the need for a runway at the same time, so why even bother with a horizontal takeoff? Just go straight up, like the Lunar Module on the Moon, or any other ballistic rocket.


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Why would a plane fly in circles?

(From FlightRadar24)
Why would a pilot fly a plane (a Piper PA-28, N41622) like this? This was around 18:00 Eastern time at Pensacola, Florida (PNS) on October 20, 2022. This plane shows as "Private Owner" in FlightRadar24 and "Vy Aviation LLC" on the FAA database. It makes several flights (most under 1 hour) per day.

Do you have a date and time for when this happened?

Do you have the registration number of the aircraft? Look it up on the FAA's website ("quick search N-number" partway down the page) and see if the owner is a flight school, or aerial survey company, or police department, or...

@SMSvonderTann yes, right before I posted the question, so about 18:00 Eastern time.

@randomhead it's owned by "Vy Aviation LLC." I'm not sure what the rules/etiquette are regarding publishing registration numbers (although I  guess it's okay because the info is already public?), which is why I didn't include it in the question.

@Someone Anyone can pick up tons of info about aircraft out there, where they currently are, who they are with ADSB. You posting here is really not letting any great secret out. Take a look at a site like adsbexchange.com, where everyday volunteers upload Gigabytes of data about planes all day every day, or liveatc.net where yet more volunteers upload hours of airband communications between those planes. As a pilot, I assume that everything I do can/will be watched by the general public. Some people register planes under LLCs/generic business names because of this.

@Azendale yeah I got all the info from FlightRadar24.

Oh, you know, there are all kinds of reasons! ;-)

@Someone For the record, many small planes are owned by groups of individuals organized under a LLC. It allows them to shield their private data somewhat from the public database it also allows them to rent out the plane to recoup some of the ownership costs. Depending on which VY Aviation this is there are several in different states, you could possibly try to determine who the officers of the llc are to try and figure out the owners. This is also a common tactic of celebrity owners of all sorts of equipment to cut down on the stop and gwak.

@RowanHawkins I'm not sure which Vy Aviation it is, but this was in Pensacola, Florida (which is very close to Alabama), so likely either Florida or Alabama.

@RowanHawkins it doesn't look like there's a Vy Aviation LLC in either of those states

@Someone The plane doesn't only have to be flown in the state or even the country where the corporation is registered. Imagine how that would work for international flights. There are in fact five or six companies in the United States listed in D&B as VY Aviation each registered in different states. This is true of all businesses and does cause customer confusion. D&B is only one source too. It could be a company registered in a county who only rent from that county and didn't seek statewide recognition.

The likely explanation is that the pilot was just making room for another aircraft.  If a plane stops in the air, it stalls and falls, so planes can't (shouldn't in normal operation at least) stop in place. Think of them like a shark, which dies if it stops moving "forward" through the medium it is in. The next best thing for a plane trying to hold its position is to just circle and stay in approximately the same place.
The square box you see with one side being a runway is a traffic pattern, which could have other planes trying to fit in in front of them. An example of this would be if a plane was making a straight in approach to the same runway while this plane was in the pattern. So to make space for the other plane to land first, the plane in the pattern just did a circle or two in place, to "pause" or "stop" where they were to yield to other traffic, without actually stopping (and thus falling from the sky).
Note that the PA-28 (Piper Cherokee) is commonly used as a training aircraft -- think of it possibly as the Piper version of the popular Cessna 172 trainer aircraft. Likely, this was someone practicing landings. Unless this flight happened from 0500Z-1130Z (very early in the morning - midnight to 6:30 AM if I'm doing the math right), they would have been operating under the direction of a ATC controller, who would likely have a training flight give way to commercial traffic, leading them to being told to circle to make way.
You can go back and look at the traffic that was in the area, according to ADSB, at https://globe.adsbexchange.com/?replay=2022-10-20-21:12&lat=30.472&lon=-87.166&zoom=13.2

For the record, I'm willing to say a stunt/acrobatics plane stops in place for an instant right at the top of a hammerhead turn.

It's a myth that sharks must move to breathe. There are recordings of sleeping sharks that lie still, breathing through their gills just like other fish do.

That replay on adsbexchange is amazing. Thanks for pointing that out!

For the record, not all sharks need to stay in motion in order to move water over their gills (although some definitely do). Nurse sharks is one common example of a species that often stays still.

Flying at a field with a significant number of large/heavy aircraft, the tower instruction, "Right 360 on downwind for spacing," was a pretty common occurrence.

I agree, if the track only shows this aircraft then they were practising doing approaches or rejected landings. Though why you would be doing that many at PNS rather than a smaller field I don't understand. They very likely weren't Landing because that would have incurred a fee.

IFR holding patterns, whether waiting for a runway or waiting for other traffic to clear when en route, tend to be ovals, although they can be distorted by wind. The standard holding pattern is straight for 1 minute, right-hand rate 1 turn 180 degrees, straight (in the opposite direction) for 1 minute, then another right-hand rate 1 turn 180 degrees.
The PA-28 looks like it is waiting, though. It looks like it is doing circuits and is interrupted by a stretch 737 coming in for a straight-in approach and landing. It lands, then a helicopter and another commercial flight lands almost simultaneously, then a C-172 goes off and circles over the bay bridge while a Airbus A319 does a straight-in approach.
That's a really busy airport, and the controller must be working hard to manage all the different types and speeds at the same time.
When I was student pilot (in a PA-28-150), doing circuits in a small city airport (pop abt 350,000), a DC-8 was also doing circuits and the controller finally told me that he couldn't accommodate my circuits while the big bird was also in the pattern, even though there was room for both left-hand and right-hand circuits at that airport.

"pop abt" is probably "population about" (approximately 350,000 inhabitants). But it did match Gregorio Luperón International Airport (IATA airport code "POP", with its corresponding city of 330,000 inhabitants...)

It does mean that, and it relates to the city I lived in during my flight training, which was London Ontario. Airport code is CYXU, which at the time (1983-84) was the approximate population as far as I remember. Those years I set myself up for an expensive lifestyle by getting my ham radio licence, SCUBA certification and Pilot's licence in the space of 24 months.

Pilot training often involves flying in circles.  Since airplanes are controlled in three dimensions, flying in a circle with reference to the ground requires a significant level of skill when you consider that the wind will blow the plane off course and the amount of vertical lift generated by the wings changes as the airplane banks.

One does not practice turns around a point or steep turns in/near an airport traffic pattern like this.


text:
What did Chuck do wrong in this Chicken Wings comic?

What did Chuck do wrong, other than being in an airplane?

IFR Hood 1; https://www.chickenwingscomics.com/wp-content/uploads/2018/09/2014-06-10-cw0684.jpg "For the ones of you who don’t have an instrument flight rating: “The hoods” function is exactly as Chuck describes it in the strip. You put this thing on and it keeps you from looking outside the window when you are practicing flying solely by instruments. That way you don’t have to actually be in the clouds (especially if you’re training in areas like California or Nevada where there aren’t a lot of clouds) and the instructor can look for traffic instead of you while flying in perfect conditions

Chuck landed blindfolded.
He's using a hood, a device worn like a visor which blocks part of your vision so you can only see the instrument panel and nothing outside. Pilots practicing instrument approaches in good weather wear such a device to simulate poor visibility, forcing them to fly the approach on instruments alone.

Aside from a few stunts that have been performed here and there, pilots never touch down using only instruments. The approach can only be flown down to a certain point called minimums. At that point you must be able to see the runway (or the approach lights) to continue. Otherwise you have to fly the "missed approach procedure."
So when practicing with a hood like this, the instructor will tell the student when to raise the hood, simulating catching sight of the runway. Chuck didn't, and continued past minimums into a landing without being able to see. In real life this would almost certainly result in a crash.
Stunts aside, only computers can land on instruments alone.

The final sentence is true for "computers and human beings" but the cartoon is about a bird that has the best flight-instruments "biologically". that was probably the intended joke, as far as I understand.

only computers can land on instruments alone. Will our AI overlords solve the pilot shortage crisis?

@GürkanÇetin I don't think that's the joke, though it's an amusing thought! The comic is about aviation and makes aviation-related jokes, not flying chicken jokes. And, I doubt a bird could land a plane, with or without instruments ;)

There could also be a reference there to a passenger flight a number of years ago which was all over the news for a bit where the nose gear jammed such that the wheels were stuck 90 degrees off-axis, so the pilot landed an unusually careful manner - totally destroyed the nose gear in the process, but the passengers all described it as the smoothest landing they'd ever experienced.

@DarrelHoffman I don't see any relation at all to the comic, but that was JetBlue 292.

It was mostly just the matter of having an unusually smooth landing in circumstances where you'd expect the opposite...

If you don't mind my asking, what makes it so likely an attempted instruments-only touchdown would cause a crash/what critical information is unavailable to the pilot from the instruments? Also, how did the pilots in those stunts manage to get on the ground in one piece?

Part of the joke is that Chuck's landings are notoriously usually bad.

@RyanJensen You should post that as a new question! There's a fascinating story of a blind person making a successful solo flight...

I find the statement "only computers can land on instruments alone" a bit suspicious without some elaboration. Are the computers using a set of sensors other than what is available to the pilot?

"only computers can land on instruments alone."
This is tautological. How could a computer land without instruments?
And, if the instruments are cameras with lasers of different wavelengths as range finders, it is quite likely that a trained pilot can land as well.

@MadPhysicist and EarlGrey and Ryan Jensen: Please ask this as a separate question. I'll have a go at answering it. It is too complicated for comments, and that's not what comments are for. Thanks!

Does "can" mean "are able to" or "are permitted to"?

@Barmar It means are able to. People, please, stop discussing this in comments. Ask a new question. I'll be happy to answer it, and that answer can then be up/downvoted, is visible to everyone, and is not subject to a character limit.

A great example of computers landing on instruments alone is the Soviet Buran orbiter, which went to space once successfully in 1988. No one would ride it, so they installed automation all the way to braking to a stop.  The computer landed perfectly, even though crosswinds were at limits.

As people of previously pointed out, the instructor is surprised that the student pilot landed the aircraft completely under the hood, without any visual reference to the runway, as is required by §91.175 for descent below minimums specified in an instrument approach.  Aside from Cat II and Cat III ILS approaches, which would be completely out of the scope of a private pilot, all other instrument approaches require there be minimum altitudes and visibility requirements to allow a pilot to descend to a runway and land.  Attempting to descend below minimums and/or land under reference only to instruments is extremely dangerous and has killed people.

What you said about CAT III ILS is correct, but it could possibly be misunderstood by some. CAT IIIa and CAT IIIb always have some visual requirements. The difference is that CAT I and CAT II have both minimum altitude AND visibility requirements. CAT III has either minimum altitude OR visibility requirements. And of course the CAT IIIa and CAT IIIb requirements are much lower than CAT I or CAT II. CAT IIIb requires autoland. If the plane has HUD pilots can manually land in CAT IIIa conditions. Only CAT IIIc has no visual requirements, but CAT IIIc is not currently used anywhere.


text:
What is the largest aircraft ever successfully flown and landed with no pilot on board?
I'm not sure if this belongs here or on the drone site.
What is the largest aircraft (not spacecraft) that has completed an entire flight, including takeoff and no- or minimal-damage landing, either on autopilot or by remote control (or a combination of the two), with no person on board the aircraft controlling it?
I'm interested in the largest by any measure (mass, wingspan, length).

What exactly do you mean by "largest"? Mass, wingspan, length, ...?

Need to define "completed" I think - does that require a no-damage landing?

@MikeBrockington yes, I was thinking of a no-damage landing, so a crash test isn't quite what I was thinking of.

A ‘good’ landing has been defined as a landing after which most parts of the aircraft are still where they’re supposed to be.

Following along on the wingspan idea, the Helios had a 247 foot wingspan.

Looked at your profile and I loved the website on there. Just thought I'd mention this to you at least once.

Depending if you go by wingspan or mass, that would either be a Boeing 720 flown by remote control for a full-up crash test (investigating how jet fuel fires start in a crash), the (slightly longer, similar span) 727-200 used in a similar test in 2012, or the Soviet Buran spacecraft orbiter, which flew a single orbital flight (boosted by the Energia core rocket, since their version had no high-thrust rocket engines of its own) completely under remote or computer control (uncrewed).

I wouldn't really call those a "takeoff and landing." OP also specified not spacecraft. +1 though. Those are probably the biggest remotely controlled things that flew.

@TomMcW The 720 was actually flown a number of times on remote with pilots aboard to verify control could be maintained -- though I don't believe they attempted a landing with remote control.  Also, Buran could be and was on at least one occasion flown from the one airport to another with the aid of "strap-on" jet engines -- though that wasn't done by remote/computer control, in my eyes, that makes Buran an aircraft with orbital capability rather than "just" a spacecraft.

I’m surprised modern airplanes are not tested with remote control first.

@Michael It's a LOT harder to land something that big from a distance of a couple miles, and put it on a runway, than it is to do it from inside the cockpit.  Ask anyone who flies both R/C and full size, R/C is harder.  Given the cost of modern aircraft prototypes (billion dollars and up-up-up), they'll fly first with pilots for a long time yet unless designed from ground up as RPV or autonomous.

@ZeissIkon: I’m wondering if remote control with proper cameras and instrumentation would really be harder. You could even integrate it into a simulator (assuming you can get the input/output latencies low enough).

@Michael I see two issues.  First, people who spend a lot of time in a simulator may become conditioned to "let it crash" where they'd take more effective recovery measures if their butt is in the cockpit -- and second, there will inevitably be issues with field of view (can't rise out of the seat and look out a side window to see if #1 is still on the pylon when the instruments go crazy, for instance) and feedback (simulators can't motion simulate extreme maneuvers).

@Michael sounds like good material for a whole new question. Feel free to ask it.

@Michael, military drones may be flown from an office thousands of miles away, but they're landed by someone standing beside the runway holding a controller.

@Michael Plane 'testing' is mostly done in simulators and with CFD. When you get pilots in the plane for the first time, they don't just take off and do a circuit and hope it lands. They taxi, they fast taxi, they rotate, none of this risky leaving the ground yet, all to prove the results of the CFD and simulators. It's quite well proved by the time you first get fresh air under the tires. The rest of the speed/altitude envelope is explored in similar incremental fashion.

@Neil_UK: Still looks like an unnecessary risk when you could remote control it. With remote control you can also test until destruction (or close to). Would also be interesting to test old planes before their retirement until destruction to see how much life they’d actually still have left in them.

Another contender could be the boeing 727-200 used for a crash experiment in 2012. It would be slightly longer than the 720 in the answer. Might be good to add that, perhaps?

I'll do so, thanks @kirgod.

@ZeissIkon The Space Shuttle Orbiter was frequently flown from one airport to another. This was done with the aid of a strap-on Boeing 747. :)

If you go by wingspan, I nominate the Boeing Condor: At 205 ft (62 m) it is in the class of the Boeing 777-300ER or the A340-600, but at less than 10 tons take-off mass it is a minnow compared to them or the Buran. Its length of 20 m puts it a shade ahead of the flying wings by Paul McCready.
Here is what Wikipedia has to say about the Condor:

In 1989, the Condor set the world piston-powered aircraft altitude record of 67,028 ft (20,430 m) and was the first aircraft to fly a fully automated flight from takeoff to landing and also setting an unofficial endurance world record in 1988 by flying continuously for more than 50 hours

Since you ask for the largest aircraft, my money is on the Condor.

One or more of the solar "airsats" likely has a larger span than Condor -- and Solar Impulse 2, with "the span of a 747" is in process of conversion to fly autonomously -- at least report, they still carried a pilot for takeoff and landing, but expect to eliminate that need soon.

Not as big, so not an answer, but it's worth mentioning that the GlobalHawk (https://en.wikipedia.org/wiki/Northrop_Grumman_RQ-4_Global_Hawk) is production UAV with 130.9 ft wingspan.

I had to read that 4 times to see that it wasn't designed by "Paul McCartney". I thought "went from a Beatle to an aircraft designer? Wow!"

@FreeMan -- seems natural enough after he was in Wings.

Ooh, good point, @PeteBecker!

When and how did this thing fly without a pilot? Maybe you want to include the relevant parts of the linked article in this post, if the article goes offline (and Wikipedia asks for money so often that I start to believe that it eventually will be offline)

@ZeissIkon - "they still carried a pilot for takeoff and landing" - ok, I get how the pilot can get off the plane so the thing can fly itself, but how does one get back on to take over for the landing?

@davidbak During the "backup piloted" test flights, the pilot was onboard from before engine start to after engine shutdown.  On the actual crash test flight, takeoff and "landing" were both handled by the remote control system.

I would suggest the Zeppelin LZ 24 "L3" of the Imperial German Navy. It had a length of 158m and a volume of 22,470 m3.

Now admittedly it was not intentionally flown without a pilot on board. On 17 February 1915 L3 was escorting a German ship heading for Africa, but after an engine failure compounded by strong headwinds and lack of fuel the captain was forced to put it down on the island of Fanø, Denmark (just north of the then current border with Germany)

The wind was so strong it blew the airship, now
unmanned but with engines still running, out to sea.

Eventually it crashed (but so did the Boeing 720 mentioned elsewhere!). Kapitänleutnant Hans Fritz and his crew were detained for the rest of the war. This airship had the distinction of participating in the first air raid on England on 19 January 1915, killing two residents of Great Yarmouth.

Fits the header, but not the actual text, of original question --


text:
Why does my paper airplane with the ailerons configured to make it spin fly straighter than with them configured for straight flight?

I made a paper airplane with a standard design, except I cut out the back ~2 cm of the body, leaving ailerons on the wings. If I throw it with the ailerons straight, it doesn't fly very far and turns to one side. If I point one aileron up and the other down, so it spins, it flies straighter and farther. Why? I've seen this effect with two planes of this design.
(Not sure paper airplanes are on topic here, or if the question would be better on Drones SE, but there's a paper-airplane tag here but not there.)

Seems on-topic to me @Someone. I think you'll need to edit with some pictures to get a good answer.

Please attach a picture of your paper airplane.

@TypeIA is exactly correct.  based on your clarification what you are seeing is spin stabilization.  Or put another way, you are seeing first-hand the benefit of spin stabilization.  If there is an imperfection in wing symmetry, the plane will tend to yaw left or right and keep right on yawing in a curved path.  But when the plane is spinning, that yaw never "accumulates" in one direction, rather you fly in a corkscrew motion around a center line.

@TypeIA would you please post that as an answer?

Or you, @MaxR ?

@Someone I've posted an answer, I hope it helps! Thanks for the updates to the question and the photos and have fun with your exploration of aerodynamics. Well done.

You're witnessing the effects of spin stabilization. It's the same phenomenon that makes rifle bullets fly farther and straighter and why American football players try to throw a spiral.
Your paper airplane has some dynamic instability: there's a positive feedback loop where a small disturbance causes an aerodynamic force that further increases the disturbance. The plane quickly goes out of control and crashes. By introducing rotation, the direction of the force is continuously varied so that the positive feedback loop is broken: the effect of the force summed through a complete rotation cancels out. You get a wobble, but thanks to the rotation it isn't allowed to develop into a full loss of control.
Spin stabilization is also used for spacecraft, but for a different reason: to give the object angular momentum which will dominate over disruptive effects of thermal radiation, gravitational gradients and other nuances of orbital mechanics, allowing one of the orientation axes (the spin axis) to stay more or less fixed. With your paper airplane, the angular momentum isn't very important, but the cancellation of disturbing forces by summing them around a full circle of rotation is.

Oh - I always thought spin stabilization was just about gyroscopic effect, but it seems not to be so.

I've experienced something similar with paper airplanes that I have built. I would attribute it to imperfections in the construction of the plane - folds not perfectly straight, angles of wings to fuselage not exactly the same, etc. Therefore, bending the ailerons to a degree which would normally produce a turn simply corrects for the imperfections in the construction of the paper plane. Just a guess.

I would think that, but it's spinning throughout the entire flight, and it flies straight with the ailerons in either direction (left up/right down or vice versa).

When you say spinning are you referring to it continuously rolling along the longitudinal axis?

Yes, rotating along the longitudinal access. Basically the same motion as a propellor on a real plane.


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What are the trim settings on ferried aircraft?
Sometimes an aircraft or spacecraft is ferried on top of a carrier aircraft. Do these "piggy back riders" have their flight surfaces controlled (possibly remotely) during the flight? If not, how are they trimmed?

I suspect the only reason why that works is that the Space Shuttle flies and steers like a brick. It's normal turn radius is 22 nm. I expect severe control problems if you tried to carry a 737 on top of something.

Has this ever been done on something other than the space shuttle?

@Ben Although not ferrying, the Air Force used to air-launch all the time testing things like the Bell X-1/X-2. Most aircraft though are usually under-slung instead of piggy-backed mostly because they are meant to be launched in flight. I haven't heard of one being ferried though, Airbus and Boeing have aircraft specifically to haul parts of airliners internally.

Some information in Could the Shuttle Carrier Aircraft do a transatlantic flight with a Space Shuttle orbiter on its back?

@RonBeyer - as I recall, the shuttle was air-launched as well for glide testing. A sort-of "throw" maneuver where the shuttle was released at the top of a climb and the 747 made a steepish dive to get out of the way.

In case of the Short Mayo Composite, controls of the payload aircraft were locked in neutral position until separation from the carrying aircraft in the air.

Thank you, this is very interesting. The related wikipedia article even mentions the Space Shuttle ferrying.


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What are the restrictions on a private pilot who is not logging time?
A private pilot can avoid the "flight time is sometimes compensation" rule by not logging the flight time.
If Bob, a private pilot, is not logging flight time, what are the limits on reimbursement? In this case, can he be reimbursed for 100% of the expense of the flight, but no more?

This may be picky, but your comment "flight time is compensation" is is not a "rule", (not in the CFRs) it is an interpretation, and it isn't necessarily true 100% of the time.  Blanket statements like this further a line of reasoning that can lead to rather absurd conclusions such as the one that prompted this question: https://aviation.stackexchange.com/questions/35609/if-flight-time-is-compensation-how-can-a-ppl-holder-legally-fly-at-all?rq=1

As I mentioned in an other comment, the FAA has a lot of tools to prosecute abuse, including the presumption that a pilot receives a tangible benefit when logging flight time. Play by the rules and you generally won't have any problems, just don't get clever or think you've found a new loophole to pull one over on the Feds.

The hypothetical exchange is something like this:

Pilot holding a PPL: I want to be paid to fly somebody/something from A to B.
FAA: You can't. Paying money is obviously compensation and the PPL generally doesn't allow you to fly for compensation. (FAR 61.113)
Pilot: OK, what about if somebody paid all the operating expenses instead?
FAA: You're getting compensated because you got to go from A to B for free. You have to pay your fair share of the expenses. (FAR 61.113(c))
Pilot: OK, what if they're letting me use their plane for free? It's banner towing or glider towing, so I don't get a free trip anywhere.
FAA: Why would you want to fly their plane in circles for free?
Pilot: I can log hours.
FAA: That's compensation. Those hours have an obvious value to you for your  future airline pilot job. Otherwise why would you provide labor?
Pilot: What can I do in that situation?
FAA: Don't log the hours. Then the flying is totally worthless to you, so you're not being compensated.
Pilot: Nuts to that. I'm not flying a banner around for no money or logbook hours.
FAA: Mission accomplished.

The key is in the linked scenario, the pilot is providing their labor for free because they are receiving logbook hours. The logbook hours have value, so that's compensation, just like cash. Not logging hours (in this scenario) is just like not accepting cash: you can't take either.

Except that some people, (many even…) for the sheer joy of flying, would be happy to fly for nothing!

Is enjoyment of flying compensation? @MichaelHall

@Someone, It depends on how you define it.  For the person willing to fly for joy, yes.  But not legally, although there is the catch-all “goodwill”.  If you abuse a situation the FAA will find a way to drop the hammer…

Nothing in the CFRs say you can be compensated at 100% as long as you don't log the time.
The standard is:  "A private pilot may not pay less than the pro rata share of the operating expenses of a flight with passengers, provided the expenses involve only fuel, oil, airport expenditures, or rental fees."
There are a few exceptions, but they don’t have anything to do with not logging time.
Private Pilot Privileges and Limitations


text:
Has anyone with no flight training ever landed an aircraft with no assistance?
There have been successful "talk-down landings" in which someone on the ground has given instructions over radio for a passenger to land an aircraft when the pilot was incapacitated, but has anyone with no flight training ever survivably landed a plane without help?
Things that don't count:

A computer does all or almost all of the work, e.g. Garmin Autoland
The aircraft lands itself without intervention, e.g. Cornfield Bomber
The person built the aircraft, e.g. the Wright Brothers

As has often been discussed, it is possible for a plane to land without any person or computer controlling it.  https://en.wikipedia.org/wiki/Cornfield_Bomber

Not precisely duplicates, but this sort of thing has been discussed at length previously: Has Air Traffic Control ever had to talk a first time pilot through a landing due to an emergency?, Can a passenger realistically replace suddenly incapacitated pilots?.

Do Orville and Wilbur Wright count?

@AnonymousPhysicist I edited the question to cover the scenario of the plane landing itself.

@RobMcDonald I edited it to exclude builders of planes.

Is this limited to soft landing or just any landing. Crash landing is hard landing hence is also landing.

@GregHewgill I'd say the first question you linked is an exact duplicate.

@user3528438 any survivable landing counts. I edited the question.

@Jamiec it's not a duplicate because that question is asking about someone landing a plane with help from ATC, while this is about someone doing it with no help.

@RobMcDonald To be pedantic, Wilber and Orville Wright landed a glider with no flight training.  When they landed planes, they already had flight training from gliders.

An interesting alternative to the "pilot incapacitated" situation, but which I believe would qualify is: Someone spends many hours with advanced flight simulator software, studies manuals for the plane they want to fly, etc. and then goes ahead and "borrows" a plane for the first flight with no instructor or radio guidance - takeoff and landing successful.

@AnonymousPhysicist I thought about that -- While I agree they had flight experience, did they have flight 'training'?  I would also posit that the question could be generalized to 'aircraft' instead of 'plane'  -- which would simply move the question to their first landing of a glider.  For that, they had experience with their kites and of course bicycles.  When do we stop including perhaps relevant experience?  Once we're talking aircraft, we shouldn't forget the Montgolfier brothers.

I just realized the title says aircraft -- while the text says 'plane'.  I'll take that to mean that gliders, balloons, autogyros, helicopters, etc. are all germane.  Of course the OP has ruled out all of these folks as the builders.

@RobMcDonald My inexpert opinion was that the Wrights intended their glider flights to be training for powered flight.  Kites have different controls.

Possibly.
On 2023 July 15, on final to Martha's Vineyard Airport, the pilot Randolph Bonnist became incapacitated.
His wife took control of the Piper Meridian and landed roughly on the grass next to a runway, damaging the airplane but
without personal injury (as the saying goes, a good landing is one you can walk away from).
It has not yet been reported if she had any training or ATC assistance.
That she missed the runway makes it plausible that she had neither pilot training nor ATC assistance.
Either of those would have advised a go-around,
had the airplane drifted off course while she was deciding to take the controls.
Any assistance from her husband must have been rudimentary.
In the brief time before landing, she may have chosen to land immediately as best as she could,
instead of wasting time figuring out how to hail ATC.
She had likely watched landings before as a passenger, but that doesn't count as training.

Hmm, I wonder if a go-around would have been a good call. If she really had zero training it might be better to take the off-runway but relatively stabilized landing then go around, risk a departure stall, and possibly end up with a less stable approach.

Good point.  That suggests the question: has ATC ever advised an untrained pilot to ditch off-runway when a go-around was technically possible?

"has ATC ever advised an untrained pilot to ditch off-runway", this is also an interesting question about the legal framework for ATCO in such situations.

@mins does ATC have some kind of emergency authority to violate regulations, similar to how pilots do?

@Someone: Neither the crew nor ATC, nor us, are allowed to violate regulations. But anyone can ignore regulations to save their life. This is still a violation you are liable for, but there is no penalty, if used with good faith, because this is like "force majeure" for contracts. However civil compensation will be due by the author in case damages or injury to others, because the law was breached. ATC would have to prove the life of the passengers was at stake and there was no other possibility. Difficult.

@mins so there's no equivalent of FAR 91.3(b) for ATC?

@Someone: I'm not a legal guy, and I may be wrong, but to me FAR 91.3(b) doesn't add anything to the rights of the pilot, it only reaffirms a fundamental right (every human being has the inherent right to life) which is part of the Human rights ratified by many States.

Almost certainly. You don't legally need any sort of training to fly an ultralight. Statistically, there are enough stupid people that it's certain many people have made such a poor decision, and they haven't all died.
If you search "flying an ultralight with no training," you can even find many such videos. No doubt, many of them built their own, but it's unlikely they all did.

I'm sure people have flown certificated aircraft without training as well. But that's illegal so people are probably more circumspect about admitting it.

Your answer likely applies especially to ultralight gliders, e.g. hang gliders.


text:
Is a nonprofit a business for the purpose of FAA regulations?
For the purpose of US aviation regulations that limit flight "in furtherance of a business," is a 501(c)(3) nonprofit corporation considered a business?

By default, yes. The regulations don't care what the tax structure of your business is.
The FAA does support some charitable organizations with relief from certain regulations. For instance, certain volunteer pilot organizations have permission from the FAA to allow their pilots to be reimbursed for some of their costs while working charitably.
It's important to note that these are exceptions that the organization has to specifically ask for and be granted by the FAA, not general rules that apply to any 501(c)(3).


text:
Would a passenger on an airliner in an emergency be forced to evacuate?
If a passenger on a part 121 airline flight on an N-registered aircraft refuses to evacuate (or insists on evacuating last, to avoid getting in others' way), would (s)he be forced to evacuate? Assume that his/her presence is not interfering with the evacuation of others.

@757toga I edited the question. Part 121, US plane

The only situations I can think of where this has happened were passengers who were injured and incapable of evacuating themselves. In those cases, ARFF (airport rescue and firefighting) crews normally evacuate them. This is why ATC wants the number of people onboard the aircraft when they declare an emergency - so that ARFF knows how many people to look for and will not be risking their own lives entering a burning airplane to evacuate people when the aircraft is already empty.

Just referring to the "insists on evacuating last, to avoid getting in others' way": I think you are much more likely to get in others' way if you do that. For instance, if there are others behind you in your seat row, you'd be holding them up; even if you have a window seat, at least some of the people passing by you are likely to stop and ask if you're okay, or tell a flight attendant that they saw someone still sitting in their seat, which will probably delay things more than if you just got up and evacuated with the others.

This is an extremely hypothetical sort of situation, since most rational people are very easily persuaded to follow flight attendant commands and leave a distressed aircraft.
In the moment, the question would be who would "force" a passenger to evacuate, and how.  The flight attendants would give verbal commands, but if those are disobeyed, very very few flight attendants would have the physical ability to force a resisting adult off the aircraft.  (Remember the passenger who was forcibly deplaned off a UAL flight by not-quite-airport-security a few years ago?  Not a particularly big guy, and it was all that the two almost-security-guards could do to get him off the airplane.  The trespasser later sued and won... further commentary omitted.) Pilots might have a little more going for them, both in average size/strength and in terms of perceived authority, but at the end of the day, I'm probably not going to go carrying an objecting adult off of the aircraft if they're determined to stay on.
As a legal matter, once a competent authority has told the passenger to leave, they're trespassing if they stay, and at some point down the road, the police (or perhaps airport crash rescue personnel) probably could physically remove them, but that point may be after the emergency that caused the evacuation has been contained.
I suppose one could posit a further hypothetical where the airplane is slowly burning (not that they tend to do that... once they start burning it goes pretty fast) and the passenger wants to stay there to die in the fire... what's the flight crew to do? Knock them out & carry (or drag) them to safety?  This is so far down a rabbit trail of improbables that I really have little idea how it would play out, other than, the person in the moment has to assess the situation & make the best decision they can.
Leaving last would scarcely be noticed, and is a rather different question... they're not being "forced to evacuate" nor resisting, they are simply the last one out the door.  Well, somebody is going to be last, and the flight attendants are at the doors, not in the middle of the cabin reordering the line of people to (hypothetically) put the wants-to-be-last person somewhere else.  Unless a traveling companion insists that the individual stand up & get into the aisle "now" rather than later, nobody is likely to force them to go other than when they want to.

I suspect they meant "legally required", not "physically forced" (since they asked "would they" rather than "should they" or "could they"). But it would be best to ask for clarification.

I expect a more likely scenario is that someone believes they'd be safer if they stay on the plane, or they don't feel like there's much risk one way or the other and they'd prefer to just wait on the plane rather than walking halfway down a mountain or whatever. Although of course the crew is presumably much more likely to know what's best in that scenario, compared to a random passenger. I don't expect they're likely to face much consequences from that, apart from possibly putting their own life at risk.

Perhaps if someone didn't know how to swim at all and was worried about leaving a dry plane to go out into a life raft. Of course, successful water landings (ditching) are rare to begin with, and when they do happen water usually gets into the cabin pretty quickly, even if the airplane doesn't break apart.

The problem is the same as those civilian "holdouts" who refuse to evacuate a combat zone.  This person is a huge burden to others, diverting resources needed elsewhere; worst of all humanitarian volunteers trying to deliver aid to them, who are then killed or wounded. Selfish indeed.
Crew need to waste time trying to convince you of the situation.  Crew also needs to make an assessment whether the issue is that you are of limited mental capacity, because abandoning a mentally-impaired person is a completely different kettle of fish than permitting a holdout to remain.   This takes time, and in an aircraft evacuation, time is life.
There have been many accidents where a minute or two was the difference between life and death - from aircraft filling with smoke shortly after evacuation, to filling with smoke while crew was waffling on a decision to evacuate. That last one resulted in loss of all onboard.  This is by design: aircraft are designed and certified to be habitable long enough for a viable evacuation.
After everyone else is off, the holdout places further burden and risk onto the crew, because they will engage in heroism to try to save the holdout.  And that is likely to get those heroes killed.
The other issue is that almost by definition, the holdout is operating on faulty or incomplete information.  They don't understand how planes are certified. They haven't seen the certification data for this plane. They don't have the situational awareness of what exactly is happening on the plane.  This is a cognitive bias in how humans evaluate risk: TLDR: we're rubbish at it.

A quote from a flight attendant concerning the evacuation of wheelchair users states that

After people have stopped coming to our assigned exit during an
evacuation, we’re trained to go through the cabin.

Which suggests that anyone who wants to evacuate last (or not at all) wouldn't come to the attention of the cabin crew until all or most of the other passengers had disembarked.
The same article has a United flight attendant saying:

My duty is to make sure every passenger gets off the plane. I will do
whatever I can to make sure the disabled passengers on my flight are
safely evacuated. If I can’t do it alone, I will find someone else who
can help me. If it is possible to get you off, you’re coming with me.
Regarding the aisle chair-anything is an option. It would need to be
reachable and available. Whatever will work in the fastest time.
That’s what we are expected to do.

Although that is in relation to disabled rather than unwilling passengers.
Apparently cabin crew are trained to drag disabled passengers off the aircraft, but I guess there is an assumption that they wouldn't be resisting.  Also, the Captain is always supposed to be the last person off, but who knows what would happen if the cabin was in flames or full of smoke and someone was arguing the point.


text:
Are Part 141 or Part 61 pilots safer?
Is there any statistical data showing whether private pilots trained at Part 61 or Part 141 schools are less likely to be involved in an accident, all else (including amount of experience, type of aircraft, etc.) being equal?

The FAA has done this study, which can be found here. The conclusion was that there is essentially no difference in accident rates between pilots trained under part 61 versus part 141.


text:
What, if anything, could actually cause one helicopter blade to be more eroded than the others?

Does this scenario in which one blade is more eroded then the others commonly occur with real helicopters? Even if it does, Julio's explanation is obviously wrong; what actually causes it?

Other than manufacturing defect there is nothing that would cause dissimilar wear on helicopter blades. The prank in the joke references the master rod of radial engine.
All the blades cut air in the exact same way. Differences in appearance are just random variations, unless some blades have been replaced for some reason, thus making the rotor assembly a mix of different ages.

Helicopters do not operate such that their rotors come into contact with vegetation.

The blade has been damaged and then replaced by another, old and worn blade from the different (same type) helicopter. From the source, blades can be damaged during the ground handling. In this case I assume quite probable that only one has been damaged.
The worn blade may be no longer airworthy or, if this depends on the results of inspection, the mechanic has more optimism if it is still good than the the previous owner of the blade. The source contains extensive overview on how do the blades erode.

No.  It's a cartoon.
The naive young student was tricked by the salty mechanic.
It's humorous, just like telling the new person to fetch a bucket of prop wash and 10' of flight line is humorous.

I do understand the joke, and I did know that Julio's explanation is obviously wrong. I was just asking whether or not one blade eroding more than others was an actual issue, and if so, what the real cause was.

Indeed.  It’s amazing how serious some people will take a cartoon…

Maybe blades are not tracked well. So one blade can be affected by some unwonted forces in flight, like vibration and twisting if out of balance
Here is an article
https://www.politicalfunda.com/2022/07/helicopter-vibration-helicopter-track-and-balance-procedure.html?m=1

"Track and Balance" is done on ground exactly to avoid vibrations in flight. No one would fly an unbalanced helicopter and in case the pilot would land as soon as possible.

Links eventually die, so I'm afraid your answer is lacking important things. I suggest you describe in a few sentences the main point of that article (but you can leave it as reference).

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.


text:
Are there "distracted flying" laws for GA other than laws against reckless flying?
I am aware of the sterile cockpit rule for airliners, but are there any laws against "distracted flying" (analogous to distracted driving laws, or the sterile cockpit rule for airliners) for general aviation pilots, aside from the general prohibition on reckless or careless flying?

What is according to you the difference between distracted flying and careless operation of the aircraft?

@Sanchises there might be cases where using an electronic device or doing something else potentially distracting isn't considered careless or reckless, but the FAA still wants to prohibit it. IIUC that's why the sterile cockpit rule exists for airliners; it wouldn't exist if any violations of it were already covered by the rule against careless or reckless flying. Also, if operating a vehicle while using a mobile device or other potential distraction was always reckless, there would be no distracted driving laws as they would be covered by reckless driving laws.

There is no sterile cockpit rule in the FARs, although most airlines have a policy.  However, sterile cockpit simply means no idle conservations unrelated to the task on hand below a certain altitude.  Nothing to do with handheld devices.

@MichaelHall the sterile cockpit rule is in the FARs in Parts 121 and 135, but not Part 91. It's in 14 CFR 121.542 and 14 CFR 135.100. https://en.m.wikipedia.org/wiki/Sterile_flight_deck_rule

Mobile device use is explicitly prohibited by 14 CFR 121.542(d): "During all flight time as defined in 14 CFR 1.1, no flight crewmember may use, nor may any pilot in command permit the use of, a personal wireless communications device (as defined in 49 U.S.C. 44732(d)) or laptop computer while at a flight crewmember duty station unless the purpose is directly related to operation of the aircraft, or for emergency, safety-related, or employment-related communications, in accordance with air carrier procedures approved by the Administrator."

I stand corrected on devices, but the conversationally sterile cockpit concept during critical phases of flight has been around long before cell phones.

What does & doesn't qualify as "distracted" in cars & what's unacceptable in aircraft can be pretty different. A long-running conversation in the car might not be distracting at all, but would violate sterile cockpit rules below 10,000'. OTOH, reading an approach plate (on paper or an EFB) is entirely allowed - and required - in the cockpit, but would be intensely distracting in a car. The differences in the environments (close proximity of other cars, capability of autopilots vs cruise control, cognitive task loading, etc) drive some pretty different expectations in the 1 case vs the other.

@RalphJ, that's a better answer than mine...  ;)

No.  Because how would observation of the infraction and enforcement work?

The same way it often happens with "distracted driving" - as part of accident reconstruction, a driver (or pilot) admits to doing things they should not have been doing.

@manassehkatz-Moving2Codidact, that’s far different than a cop pulling someone over after seeing them texting while driving.  Distracted driving laws are intended to prevent accidents.  Once an accident happens it’s too late to do any good.

That is true. But I think (could be wrong) that in the case of a car accident, they can charge a driver with "distracted driving" or similar, if they believe that is part of the cause of the accident, much as DUI can be charged both at a routine traffic stop and after an accident. Whether similar rules apply for flying, I don't know.

@manassehkatz-Moving2Codidact, True, but given that aviation accidents generally have far more dire outcomes, such a charge after the fact would just be piling on.  Again, these sort of laws are intended to be preventative by discouraging behaviors that might lead to an accident.


text:
Could medevac/air ambulance flights take off during the NOTAM system disruption?
While the NOTAM system was down on the morning of January 11, 2023, was there a way for medical flights to take off legally and safely?

Legally special case flights took place during the 9/11 shutdown. Exceptions to closure orders can be made.

Both "legally" and "safely" would depend on your point of view and the specifics of each individual flight.
At its core, a ground stop is one tool in the Traffic Management Initiative toolbox; controllers implement ground stops in accordance with JO 7110.65 Chapter 4 "IFR" Paragraph 4–3–5:

Do not release an aircraft if a ground stop (GS) applicable to that aircraft is in effect, without the approval of the originator of the GS.

TMIs are generally thought of as applying to IFR aircraft only; it is common practice for IFR aircraft facing a lengthy EDCT to elect to depart VFR and remain below Class A airspace all the way to their destination, for example. However there is historical precedent for a VFR ground stop: on September 11, 2001, a message was issued to Air Traffic facilities saying:

GROUND STOP ALL TFC ALL DESTINATIONS ... THIS INCLUDES LOCAL FLIGHTS / IFR / VFR / MILITARY FLIGHTS ... NO ONE FLYS

Again: this was a message sent to Air Traffic facilities, not pilots. A VFR departure from a non-towered airport would not have known about this ground stop. But a VFR aircraft at a towered airport would have been told not to depart, and would have had to comply with that instruction per 14 CFR 91.123(b).
In the case of the GS on January 11, 2023, the message was:

GROUND STOP ALL DEPTS REGARDLESS OF DESTINATION

which certainly sounds like it applies to "all departures." But just like on 9/11, this message was only sent to ATC—and because the NOTAM system was out of service, the FAA could not issue a general TFR that pilots could see during a pre-flight briefing.
Now there were additional messages sent relatively soon after the initial GS message which exempted first medevac and military flights, then VFR flights, and then IFR general aviation (Part 91) flights. But for a short while, VFR aircraft—even medevac VFR aircraft—were not allowed to depart towered airports... depending on how controllers at those airports interpreted the GS message.

As for the "safety" aspect: Pilots have a legal and moral obligation to familiarize themselves with possible hazards prior to beginning a flight. 14 CFR 91.103 requires that pilots "shall, before beginning a flight, become familiar with all available information concerning that flight." If the NOTAM system is not operating, recent updates and outages in the National Airspace System cannot be found by pilots.
The FAA seems to have decided that that information being unavailable constituted an unacceptable safety risk, particularly for airline flights—hence the general ground stop. But a medevac helicopter crew departing from a hospital and landing back at that hospital entirely in Day VMC may have looked at the situation and decided that the lack of NOTAMs did not constitute an unacceptable risk.

Thank you! What does "TFC" mean in the 9/11 ground stop? "Traffic"?

Yes, "traffic."


text:
How can I determine how long it would take to fly between two points?
How can I determine the approximate time required to fly a particular plane (e.g. a Cessna 172) between two points, considering the possibility of needing intermediate stops? For airline flights, I can just look it up online; is there something similar for GA? I'm considering getting a license and plane at some point in the future, and there are two cities quite far apart that I'll be traveling between fairly frequently, and I would be interested in seeing if it would be feasible to make that trip in a plane I could possibly afford at some point.

I assume you know speed * time = distance?

@TypeIA yes, but I don't necessarily know if a Cessna can make it from point A to point C in one trip, or if I'll have to add a point B in between.

That wasn't really clear as part of your question. Maybe you could edit it and describe the kind of scenario you're trying to understand. Are you really asking how to calculate_range_?

But you can look up the range of a C172 and divide. Then you’ll need to know how long to plan for each fuel stop.

You'll probably need to give cities/airports. Otherwise, ignoring climb and descent, the 172 has a cruising speed, fuel "mileage", and tank sizes.

Don't forget that you won't be able to go at all unless the weather is decent (unless you get an instrument rating which is much extra cost.). Depending on what part of the country you are talking about and what part of the year, you may find that personal aviation is really not a very practical, cost-effective option for personal/business travel, at least from the viewpoint of someone starting out with zero experience/ credentials. And especially considering the fairly high speed limits on most highways now.

(If the time of one extra fuel stop is a potential deal-breaker, then it's unlikely that this option is going to turn out to be a good one for you.). But hey if you decide to get your license anyway-- more power to you! None of which really answered your actual question, but...

Maybe you could finance your flight training by creating and selling an app that did what you are asking?

@quietflyer that's a good idea!

Fuel stops shouldn't be a problem (other than the cost of fuel); I just wanted to see how many would be required.

(I'm seeing now that an existing answer points out that some existing, subscription-based services do address this need.  Still, maybe you could do it better!)

No, there's no such service for GA pilots. In fact, there's no service for commercial planes, either; the only way you know ahead of time how long a particular flight will last is because someone at the airline calculated it and then published their numbers. Unfortunately, as a private pilot, you don't have a company to do your math for you, so you have to do it yourself. (There are apps, such as Garmin Pilot or ForeFlight, that will do it for you, but they aren't free.)
To help your decision whether or not to get your license, airplane manufacturers will publish the typical effective range for their planes. You just need to get a map and a ruler, measure the distance between the airports you plan to fly to, and see if one number is less than the other.
The time required is much the same. Divide distance measured by published cruise speed to get time. This won't be precisely accurate (your plane doesn't fly as fast when climbing, you might have to navigate around obstacles, etc.), but it will at least get you in the ballpark.
If you do decide to get your license, part of the classroom training will be on flight planning. You'll learn how to use a map and a winds aloft table to calculate your exact flight time, fuel usage, etc. for any given flight. And part of that is identifying airports near your flight path that could be used if you wind up burning more gas than you calculated and have to stop for a fill-up.

Thank you! The route I want to travel would be at least four stops in a Cessna 172S. It's about 2,200 nm.

I just found https://www.simbrief.com/, which seems to do what I want, although it's designed for simulators and apparently cannot be used for real flights. It does seem to give a good estimate though.

apps won't just give the answer either, you must enter all the specific info.

Range in miles isn’t perfectly reliable since it depends on winds aloft, which vary by hour and by altitude.  If you find a single number for a given plane, be aware that it does not account for this.
More commonly you will see range given in hours.  If not, you can calculate it from the size of the fuel tanks divided by the fuel consumption per hour and then subtract an hour for reserves.  You can get no-wind range in miles by multiplying that by the cruise speed.
While that number isn’t good enough for real flight planning, it’s good enough to get a general idea of whether a trip is practical, or roughly how many fuel stops you’ll need.
In the example you gave in a comment of 2,200nm in a C172, we can guess that would take about 20 hours.  For a rare event where the trip itself is the point, such as a fly-in like EAA Airventure in Oshkosh, WI, that might be reasonable.
For something you’ll be doing “fairly frequently”, though, that seems ridiculous.  You’d want to look at a significantly faster plane, which will take you time (and money) to work up to.
Also, keep in mind that GA is rarely cheaper or faster than airline travel, nor as safe or reliable.  So unless one of your points doesn’t have airline service, this plan doesn’t seem remotely realistic.

I should have clarified; "fairly frequently" is a few times a year at most, likely just twice, if it ever happens.

2,200nm in a C172 is just.... ouch. Your bladder and your backside will not thank you.


text:
Is careless or reckless operation of an ultralight illegal?
Is flying an ultralight in a careless or reckless manner illegal?

Are you below 83 feet, on your own property, and is no one else present?

Is this referencing a specific event or occurrence?

@Mazura what is the significance of 83 feet?

@RockPaperLz-MaskitorCasket no, just a general question

United States v. Causby, 328 U.S. 256 (1946), was a landmark United States Supreme Court decision related to ownership of airspace above private property

Doing anything carelessly or recklessly (i.e. in a manner that puts the lives of others at unnecessary risk) is illegal. Flying an ultralight is no exception.

§ 91.13 Careless or reckless operation.
(a) Aircraft operations for the purpose of air navigation. No person may operate an aircraft in a careless or reckless manner so as to endanger the life or property of another.
(b) Aircraft operations other than for the purpose of air navigation. No person may operate an aircraft, other than for the purpose of air navigation, on any part of the surface of an airport used by aircraft for air commerce (including areas used by those aircraft for receiving or discharging persons or cargo), in a careless or reckless manner so as to endanger the life or property of another.

Careless and reckless doesn't mean what many people seem to think it means, so here are the definitions given in Wikipedia. Put simply, if you were being careful enough to ensure you were not doing dumb things near other people, then you are not actually being careless, are you?

Recklessness: willingly taking an initial action that a reasonable person would know will likely lead to the actus reus being committed, e.g. drinking alcohol and then driving as a result of automation due to intoxication.

Carelessness (also known as negligence): failing to exercise due diligence to prevent the actus reus that caused the harm from occurring – rarely used in criminal law, often encountered in regulatory offenses (e.g. careless driving) or in the civil law tort of negligence – these are known as strict liability offenses.

Source for both the above quotes: https://en.wikipedia.org/wiki/Recklessness_(law)

"Doing anything carelessly or recklessly (i.e. in a manner that puts the lives of others at unnecessary risk) is illegal." -- give some thought to this sentence: "I've been really careless about keeping up with oil changes on my car, and now the motor is all worn out."  Later you mention "the actus reus that caused the harm".  If we are talking about doing anything carelessly, it is not obvious that the potential harm will always involve some other person or some other person's property.  So your "i.e." clause appears to be a false equivalency.

Random Wikipedia word definitions are not a useful answer to a question of law.

If the question was whether or not 91.13 applied to ultralights I would agree, otherwise I generally disagree with the comments above.  (You don't have to cite 14 CFR part 91.xxx to answer a question as to whether flying airplanes into the WTC was illegal.) And Quiet Flyer, your maintenance practice is likely to result in premature engine wear before putting other lives at risk.  The other answer is better, and more aviation oriented, but this one is correct and I don't think deserves to be downvoted.

It's reasonable to say that a 5th grade student was careless doing her homework, but it's not reasonable to say that this rises to the level of any form of legal offense.  The statements are over broad and as such aren't helpful in addressing the very specific question asked.

@quietflyer - What thought is needed? you've been careless with the oil changes in your car and you've been careless with oil changes on a commercial aircraft. One puts the lives of others at risk, one doesn't. Lack of care is not a crime. Endangering others is.

Current and future commenters:  Please read the qualifier in the second sentence in parenthesis!

The top answer emboldened the wrong part:  to other persons or property, +1. You can do w/e you want to your stuff on your property. Involving other persons or property changes everything and need not be aviation specific unless the title said so.

I'm downvoting because careless and reckless behaviors are absolutely permitted by the FAA, so long as they don't endanger others. Wikipedia definitions are useful for lay arguments, but not for analyzing a century of case law. It is my right as a pilot to drag wheels on the water, to do low altitude high-speed passes, to put my plane into an inverted spin, or to build an experimental with rocket propulsion. All of these might be reckless to my safety, but so long as it is not (and cannot be construed to be) to others then the FAA is permissive.

Upvoting. His clear point was that "Flying an ultralight is no exception" for making actions legal or illegal. "Doing anything carelessly or recklessly (i.e. in a manner that puts the lives of others at unnecessary risk) is illegal,"  seems hard to misconstrue. If an action is illegal in normal activity, then it is while you're flying.  "Doing anything carelessly or recklessly in a manner that puts the lives of others at unnecessary risk" as a simple example. Changing your oil generally isn't illegal, so doesn't fall under the purview of this answer.

@KennSebesta - Thank you. You forced me to find the actual FAA rule 91.13. The FAA are not permissive. Behave in a manner that is clearly reckless, and they will get very interested. Step over the line and put someone else at risk and they will come down on you like a ton of bricks.

@PaulSmith the FAR says "No person may operate an aircraft in a careless or reckless manner so as to endanger the life or property of another." That FAR is exactly what we've made it out to be: the FAA literally only cares if you are endangering "the life or property of another". If you are not, then 91.13 simply does not apply. Do you read that differently? If so, could you point out what in 91.13 supports an argument that the FAA is "not permissive" and "will get very interested"?

@BWhite where in the OP's question is there a comment made re 91.13? The question, as I and many others read it, is "is it illegal for me to do dumb things with ultralights, aka Pt 103 aircraft"? There was no qualifier which shows the OP is asking about doing reckless things near others. If you choose to focus just on reckless actions with other people around, then I think we all agree with 91.13. But reading 91.13 attentively lets us conclude the FAA has two categories of "reckless operation": 1) when people/property are around and 2) when they're not. The FAA doesn't care about the latter.

@KennSebesta - Careless doesn't mean what you seem to think it means, that is why I gave the definitions. If you were being careful enough to ensure you were not doing dumb things near other people, then you are not actually being careless, are you? I am updating the answer to include this.

@PaulSmith I think you're forcing a definition of "careless" which is not supported by the FAR. The mere fact that the FAA sees the need to qualify careless for the purpose of 91.13 is proof positive that there can be "careless" operation without anyone or anything around. Can you find any case law support for 91.13 being applied in an expansive way such that there are, in practice, no careless actions which would not fall under 91.13? If so, I would switch my downvote to an upvote.

@PaulSmith you might read https://aviation.stackexchange.com/a/87090/20394, and in specific the given example of not putting landing gear down. I think an pilot who forgets to put the landing gear down would always be careless, but this would only be a FAR violation if that happened in a place where it could endanger others, e.g. a public airfield as opposed to one's own cow pasture. You might also review https://aviation.stackexchange.com/a/91985/20394 for its highlight examples of "careless" operation, many of which would be allowed in a private context (e.g. running the engine unattended).

@KennSebesta - Sorry but you are still looking at this backwards. Of course you can be careless when no one is around, so what? Read the legal definition again, the fact you are being careless means you have not shown the due diligence required to know that no one is around. If you go somewhere where there is nobody to do your dumb thing, then you are not being careless.

@PaulSmith your statement is in contradiction to the tables on pages 4-15 and 9-22 in FAA Order 2150.3C - Compliance and Enforcement Program (https://www.faa.gov/documentLibrary/media/Order/FAA_Order_2150.3C_CHG_7.pdf). Actions such as a gear up landing are defined as careless, without consideration to the presence of others. A definition of careless is given on Page 9-3 and again does not require others' presence. Reading the FAA's definition, would you argue that an accidental gear up landing is only careless if there are no people around?

@KennSebesta  You seem to be arguing both sides.
"Yeah, basically. The FAA's mandate is not to protect individuals from the consequences of their actions, it's to protect the public and all the other people those actions might hurt." I agree with you.
"Actions such as a gear up landing are defined as careless, without consideration to the presence of others." Which is it?
"@BWhite where in the OP's question is there a comment made re 91.13?" Not directly. What's your point?

@BWhite "That's not the way I would do it, but I can't stop you," is a ubiquitous refrain, from financial investing to eating habits to romantic partnerships. As we've established, the FAA doesn't have a rule against careless operation when there's no one around, and yet the FAA still defines these behaviors as careless. I fail to see a both sides argument here.

@KennSebesta , I hate to be pedantic, but I can't tell what your point is.  Exactly which part of "Doing anything carelessly or recklessly, that is: in a manner that puts the lives of others at unnecessary risk, is illegal. Flying an ultralight is no exception." do you take issue with? In some of your answers, you seem to be agreeing with it. So what's your disagreement?

@BWhite my disagreement is with the "i.e." and parentheses. I would agree completely with "Doing anything carelessly or recklessly in a manner that puts the lives of others at unnecessary risk is illegal". Putting that in a clause, however, indicates that merely doing things carelessly or recklessly is proscribed by the FAR. This is not correct, as has been shown above. And while "i.e." could be ambiguous in this context, the comment train gives it clarity. P.S. I feel like our positions are now well understood, so I'm going to bow out unless there's something helpful I can add.

@KennSebesta - That is not what recklessness is. It is not actually putting lives at risk, it is likely to put lives at risk. Its pedantic, but its important. It is why doing the same dumb thing is not illegal if you have taken precautions that no one could be hurt.


text:
What is the longest recorded nonstop flight made in a Cessna 172 without receiving external fuel?
What is the record for the longest flight (by either time or ground distance covered) made in a Cessna 172 without obtaining fuel from an external source after take-off? Extra fuel tanks are fine, as long as the plane took off with all of the fuel it burned during the flight. Only flights that landed safely count, but it does not matter if they complied with fuel reserves and other regulations or not. I'm looking for a specific flight, not an estimate of the longest possible flight. For example, a C172 has been flown from Merced, California (KMCE) to Honolulu, Hawaii (PHNL), a distance of 2,521 miles. Perhaps this is the record?

@MichaelHall longest that landed safely; landing on fumes counts but crashing does not. How would it be calculated? Is there a way to determine the largest possible extra fuel tank someone could take?

@MichaelHall how was this flight taken? https://www.flyingmag.com/how-far-would-you-fly-a-cessna-172/

As for reserves, it doesn't have to be landing on fumes, but if the longest recorded flight did land on fumes, I would accept that answer. If the longest recorded flight complied with reserve requirements, that would be the answer.

It's likely that the longest publicly documented flight, and possibly the longest flight, did have adequate reserves, and if so, that would be the answer, but it isn't a requirement for answering the question.

@MichaelHall It might be the longest, but someone else might know of a longer flight. I didn't know about that flight until today, so it is certainly possible there has been a longer one and I haven't heard of it.

Fair enough, maybe somebody will chime in here...

Are you looking for a specific instance, or is this more a thought experiment a out how one would fly the maximum possible distance without refueling?

@MaxR I'm looking for a specific instance.

Does it count if they refuel mid-air?

Was it Charles Lindbergh?

@TomMcW no, it doesn't count. Any flight that received fuel from an external source does not count.

@RobertDiGiovanni I don't think the Spirit of St. Louis was a C172 :)

A Cessna 172 flew non-stop, no refueling, from Merced Regional Airport (MCE) CA to Hawaii, at a distance of about 2,190 NM (4,055 kilometers), in about 18 hours.
The Ferry Tanks provided an additional 157 gallons of fuel, beyond the 53 gallon standard tanks.  The estimated range with the extra fuel was around 2,500 NM, so they weren't even really at the limits going less than 2,200NM.
So, yes, as best I can find, that ferry flight is the longest recorded flight.  Although, around 2,500 miles (+300 more) is theoretically possible.
The full story is at https://www.planeandpilotmag.com/news/the-latest/2022/08/30/the-story-behind-the-cessna-172-that-flew-from-california-to-hawaii/
Or also at:
https://avgeekery.com/a-cessna-flew-18-hours-to-hawaii/

Around 2800 lbs.  Overweight, but a bit safer.

I believe its only 2800 lbs if configured normally.  But there is a high likelyhood that they removed seats and anything non-essential to save weight and make more space for fuel.  I couldn't find anything in the articles that specifically mentioned removing seats, but it is a common practice for ferrying.

@abelenky do they send the seats by a delivery company like FedEx or UPS when they do that?

In many cases, yes, the seats are removed as the ferry-tanks are installed, and can be shipped separately, arriving at the destination before the plane.  If its a brand-new plane, the buyer may even ask the seller to never install the seats, and ship them directly to the destination.  Especially in a C-172, removing seats is no big deal. (I personally helped removed seats to make extra space for camping equipment)